Collapsible containers and crates are commonly used to transport and store a variety of items. Such crates are typically formed of injection molded plastic and are frequently adapted to receive perishable food items, such as produce. When assembled, such containers are rectangular in shape, and have a flat base surrounded by four upstanding flat side panels which are joined to the flat base. When the containers are not in use, the collapsible feature of the containers allows the containers to be folded or otherwise reduced in size, thereby providing a desired compact size when storage space is minimal.
In such collapsible containers, side wall edges are normally joined in the corners. However, for an assembled container during use, this corner system results in a less rigid container due to the corners being subjected to torsional and other bending forces during use. Accordingly, the corners are commonly a focal point of stress in containers of this type.
Moreover, the base of the container is subject to a relatively large amount of load when the container is filled and may frequently be lacking in the area of stability and strength. Because these containers often stack on top of others or may have other loads exerted on their upstanding panels, the side panels may also require enhanced strength. Typically, when a rectangular container is collapsed inwardly, first the long walls are collapsed and then the short walls are collapsed on top of the long walls. Because there exists a gap between the short walls when folded, a container stacked thereupon is not fully supported in the area of the gap. Also, because one container rests upon the walls of another container, any transfer of top load forces is transferred through the walls, which may reduce the durability of the container. Other containers may fold the short walls first and the long walls second, but this configuration requires a reduced long wall height, because for ideal nesting conditions with other containers, the long walls in this type of container should not overlap when folded.
Further, containers are also shipped on pallets and are commonly strapped together to secure them during shipping and transport on the pallets. Such palletizing of the containers is often done automatically by machinery which may improperly position the straps, or subject the containers to unnecessary stress.
The improved container should be capable of stacking with similar containers when assembled and nested with similar containers when folded. The container should also have a sturdy construction and load-bearing properties. The container should avoid the durability concerns of nesting a container to rest solely on the walls of the container therebelow. The container should also accommodate the palletizing procedures when containers are strapped together.